#include <stdio.h>  
#define PI 3.1415926  
  
int main() {  
    int a, b, c;  
    if (scanf("%d%d%d", &a, &b, &c));  
    if (a + b < c || a + c < b || b + c < a)  
        printf("non-triangle.\n");  
    else {  
        if (a == b  && b == c)  
            printf("equilateral triangle.\n");  
        else if (a == b || a == c || b == c)  
            printf("isoceles triangle.\n");  
        else  
            printf("triangle.\n");  
    }  
    return 0;  
}  